i have seen some guys saying that they have taken out the plastic bushings for radar runs. does this give u a gain ? if so why? and have anyone tried different clutch kits in the rer`s? and if so how did they run?..... and finaly have anyone eles noticed the secondary loosing its tention and not realy being able set the spring in another seting. now i know lots of questions...........lol so lets have the answers..........lol :D

Oh am I glad you asked! Do not take out the plastic bushings on the secondary. Take the spring and collapse it fully in a vise. Then heat it up some 200F ??? I'm guessing on the temp but not hot enough to hurt the paint, its too hot if you do that. Then let it sit for awhile. Repeat the process until you drop it one inch in height MAX, don't go overboard or your buying a new spring! Then reinstall, and set your clickers to run just below your hp peak. Oh, then hang on! I would not waste time changing the helix on a stock sled. The stock one is pretty much perfect for fast trail occasional lake racing. If you really must get a new helix, Cudney offers one that is "one step up" from stock. DO NOT go higher than that for a stock sled. Bill knows the numbers and he will recommend that you be conservative on this issue. You do not have to mess with the secondary on the RER like you did the old secondary. Focus on the primary for the best upshift. (Thundershift) Good Luck!

fast mach z are you saying to leave the secondary alone and just play with the primary clutch stock spring.yes my mach1 99 has rer.. thanks

thankz i will try that.. and ive noticed from the crank shop they recomend to stay with the stock helix but to go with a 286 ramp or a 280 ....what did u do for the primary

Yes, I'm saying that the secondary is not where you need to spend your time. It can be "tweaked" a tad, but it is a huge improvement over the old style secondary. It is like a non-roller, roller! It really is that good. You really want to work on the primary for upshift. On the Mach Zs with the stock ramp, I have had much better luck than the guys that change ramps to either the 280 or the 286. Once you change ramps, the whole primary has to be retuned from scratch. On stock sleds, the guys who change the ramp are usually easy pickings to beat. Now, if your a really good TRA tuner, then maybe you can change the ramp and do slightly better, but from what I have seen, most of them slow down with the ramp change! Now that is on Mach Zs, on the other Doo twins, I don't know what the hot ramp set up is. But there are plenty of guys on these boards who have done a lot with them. Your at the right place!

I have an 02 800 MXZ. I am using a 52/46 helix right now and a 185/290 spring in the secondary (The stocker is a 165-175/320) along with my own arms. Seems to work really well, however we ran out of weather last year before I really had a chance to dial them in. I wasn't studded last year, but I am now. That will chcange things. I have not tried any different ramps, but would be very interested in what you guys have tried.

Fast MachZ... Are you shortening the spring to allow the primary to shift with less resistance (or feedback) from the secondary? I'd like to know your take on the science of shortening the spring. Sounds like a good idea.

idooski, if you were to graph the spring you would find that shortening it keeps the rate the same, but it shifts the entire line on the graph over. So, at any point in the operation of the secondary, you have less spring pressure to contend with. This will allow the primary a little more shift pressure. But, it is not a lot. I really did it because the steady state rpm of the motor was too high. Since the secondary give instant backshift, you can let it shift out a little more when riding at a steady speed. You gain gas mileage and motor longevity. I'm really looking for someone to market aftermarket springs for the secondary. I want one to start at close to the stock pressure but have it hardly go up or just a few pounds as it is compressed. That is a future experiment though. I also will be playing with the Thundershift as some point this year. I want to see if it really makes a difference or not over a well tuned factory set up. I also really want to hook up with an owner of an 800 Doo twin so I can play with the clutch. Everyone says they are dogs. I want to get the chance to wake one up. Well, that is a lot of stuff I'd like to do!

Fast Mach Z... Where are you from? You don't have the location filled out for your profile.

My 800 is not a dog. Maybe I just got lucky. Maybe I pay a little more attention to detail. Sounds like a good little trick with the spring, but in my present s/u I don't think I could pull a softer spring. I have put a stiffer one in already to keep the R's up at the bottom just a little longer, but it is softer at the top. I have made my own arms for the TRA. Seem to work pretty good at softening the blow at engagement. I may make a set for TRA3 on the REV when it gets here if it feels like it could use them.

Hey there,
New to the board. I am very interested in the topic, but am i limited because of the rer and dpm?. I have a 2002 mxz800 adreneline. While i don't think my sled is a dog, i just want to get the peak performance it is capable of. Any tips on tuning the sled would be much appreciated :) Keep in mind I weigh about 205, Would that dictate some particular clutch adjustments? Thanks Guys :)

Not at all limited by RER and DPM. Last year was a little different because of the limited supply of helix's for the secondary. The DPM in no way inhibits what you can do in the way of jetting. You can still pipe it or what ever you want. Where and how do you ride and just maybe we can help.

Ride northern Maine mostly and Nh. Lots of wide open trails and lakes. Like to do a little buddy racing. Don't care about top end as much as wanting to leave in the snow dust :D

i was actualy thinking of just trying to get a straight angle helix like a 50

First of all the RER secondary spring is not adjustable the way the standard converter spring is, there is no adjustment to the spring tension or pressure, the stock Ski Doo RER spring at about 1000KM (600miles) or so has a tendency to sack out, they are a lot of RER helixes avaiable, we have 20 different ones from multi angle to straight ones and we also have different RER springs that don't sack out, the biggest problem with the SD RER spring in the MXZ platform is that it doesn't let the converter grab the belt as well as it can,the higher rate spring allows the converter to keep ahold of the belt. -- Bill

HEY BILL; I AGREE THE SPRING DOES GET SOFT AFTER NO TIME AT ALL. I DO HAVE SETTINGS ON THE ONE SIDE OF THE CLUTCH BUT FOR SOME REASON IF ITS NOT IN THE THIRD HOLE IT JUST LOOSES ITS TENTION. ANOTHER THING IS THE 2 PLASTIC BUSHINGS ONE IS LIKE A CUP AND ONE IS LIKE A WASHER WITH 1 FLAT SIDE. THE WAY MINE IS IS THE WASHER TYPE IS IN THE BOTTOM THEN THE CUP WICH THE SPRING SITS IN IS THIS RIGHT? BILL I WILL BE GETTING A HOLD OF U FOR SOME CLUTCH PARTS ;)

Hey, Bill wieghed in this one personally! You guys should feel lucky. Bill has a lot of expeience with the twins and I have none. Go with his advice and be prepared to tune a little to get it all "just right". Like I said he has helixs in stock, and one that is one step up from stock. But, while your at it, have him port the motor too!

Machz69, the stock SD secondary spring is a 1 tine spring that you can install in a hole in the bottom, the aftermarket springs have no tine on them they are just like a primary spring, the location of the tine in the secondary through all of our testing and according to Ski Doo has no effect on the way the converter works. The plastic cups that you have described are in the correct position and by the way the removal of them has no effect on the snowmobile the reason for the palstic is a possible gauling that may be caused by the spring. -- Bill